US Supreme Court Rules Probability Of Trump Tariff Being Illegal Is 72%

According to the real-time data from the Polymarket platform (as of December 20, 2025).The price of the "Will the Supreme Court rule in favor of Trump's tariffs?" "Yes" option in the market is approximately 28 cents, which implies a 28% probability of supporting legality, i.e., a 72% probability of ruling illegal.

This prediction reflects traders' pessimistic expectations regarding the case.Especially since the Supreme Court's oral arguments on November 5, the probability of "Yes" has plummeted from a high of 47% to the current level of 28%.。

According to the procedures and current progress of the U.S. Supreme Court, the case (mainly referring to Trump v. V.O.S. Selections, Inc., No. 25-250, and the consolidated Learning Resources, Inc. v. Trump, No. 24-1287) has not yet reached a final decision. As of December 20, 2025, the Supreme Court held oral arguments on November 5, 2025, but the opinion has not yet been released. The Court typically issues its rulings before the end of the next term (i.e., by the end of June 2026), so it is expected that the decision in this case will be released before June 2026, or possibly earlier (likely in the first half of 2026).

Case Progress Timeline

In April-May 2025, the lower court's preliminary ruling:The Court of International Trade (CIT) and the District Court for the District of Columbia both unanimously determined that the reciprocal tariffs and trafficking tariffs imposed by Trump under the International Emergency Economic Powers Act (IEEPA) were illegal, and issued a preliminary injunction (which was later stayed).

📌 On August 29, 2025, the Federal Circuit Court of Appeals ruled:The majority opinion, with a 7-4 vote, confirmed that the tariffs exceeded presidential authority, and the appellate court upheld the injunction.

📌 September 4-9, 2025, the Supreme Court will hear:Certiorari granted, consolidating two cases, setting expedited review.

📌 Oral Debate on November 5, 2025:The focus is on whether the IEEPA authorizes the president to impose tariffs and whether it unconstitutionally delegates legislative power. The Supreme Court questions the government's position.

📌 The final ruling by the first half of 2026 (by the end of June at the latest):The Supreme Court's OT 2025 term will be announced before the end; if urgent, it may be announced earlier.

The Trump administration announced that the new tariffs imposed in 2025 will exceed $200 billion in revenue. If ruled illegal, it may lead to refunds of over $200 billion in tariffs that have already been collected.